1. Field of the Invention
Embodiments of the present invention are related to a digital watermark embedding device, a digital watermark embedding method, and a computer-readable recording medium.
2. Description of the Related Art
In the voice signal processing technology in recent years, it has become possible to synthesize various voices. However, it also involves risks such as impersonation with the voice of an acquaintance using the synthesized voice or misuse of the voice of a notable public figure. Moreover, because of being able to generate an imitated voice (a resembling voice) of somebody else, it is not possible to rule out a likely increase in impersonation frauds using the voice of acquaintances or a likely increase in criminal acts such as defamation by misusing the voice of notable public figures. In order to prevent such crimes from occurring, a technology has been developed in which a digital watermark is embedded in a synthesized voice so as to distinguish it from the real voice, and any misuse of the synthesized voice is detected.
Meanwhile, in the media contents in which resembling voices are created using the voice synthesis technology, in case the expressions that are banned in broadcasting, such as discriminatory terms or obscene expressions, are included or in case the expressions associated with crime are included; if such contents are mistakenly used, it may lead to a trust issue for the person whose voice has been resembled. In that regard, in a device capable of generating such synthesized voice, in order to deal with a case in which expressions that are banned in broadcasting are included, it becomes necessary to have a function for embedding an accurately-detectible digital watermark while maintaining the voice quality. However, there has been no proposal for implementing such a function in an effective manner.
Therefore, there is a need for a digital watermark embedding device capable of embedding a digital watermark having high detection accuracy while suppressing a degradation of the voice quality.